<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>2.39</title>
</head>

<body>
    <script>
            //报错1
            export 1;

        //报错2
        var m = 1;
            export m;

        //正确写法一
        export var m = 1;

        //正确写法二
        var m = 1;
        export { m };

        //正确写法三
        var n = 1;
        export { n as m };
    </script>
</body>

</html>